Some conventional guided munitions have movable fins which control their trajectories during flight. The fins, which are located outside the munition shells, move in various directions to steer the guided munitions through air (and/or water) to their intended targets.
For such a conventional guided munition, a guidance system typically resides within the munition shell. The guidance system typically includes a processor, motors, and motor linkages connecting the motors to the fins. During flight, the processor operates the motors which drive their corresponding linkages to move the fins. With the fins disposed on the outside of the munition shell, and the fins aerodynamically guide the munition to its intended targets.
Examples of conventional guided munitions include rockets, guided missiles which are fired from the ground, and guided bombs which are dropped from aircraft. Some conventional torpedoes also have movable fins which enable the torpedoes to change course after launch.